Last fall, Pinellas school district officials had high hopes they could use $21.7 million in emergency federal money to soften the blow of next year's massive budget cuts. But most of it has been gobbled up by unexpected costs.

The main culprit, district officials said: the hiring of more teachers to meet class-size limits.

The district banked on 80 fewer teachers than last year, assistant superintendent Kevin Smith said. They ended up with 42 more. At roughly $62,500 a pop, those 122 extra bodies are costing the district about $7.7 million.

"I'm just floored," School Board member Janet Clark said Tuesday. "I don't understand it. I really don't. I need to know why we were off by that much."

At issue is money from the federal Education Jobs Funds and the "cliff reserve" — the money the district set aside to make cuts less severe when federal stimulus money runs out this year.

District officials said last fall that much of the jobs fund money — a one-time bailout that went to school districts around the country — would be used to build up the cliff reserve. Budget documents show the reserve ballooned from a projected $12.2 million when the budget was passed in September to a projected $33.8 million when finance officials crafted a budget model in December.

But the latest budget models show the cliff reserve has shrunk to $15 million. And district officials are now pointing to several expenses that have been bigger than anticipated.

"We've been reasonably accurate in the past" with teacher projections, Smith told the board at a workshop Tuesday. "But it's hard to be definitively accurate."

Smith noted the projections for the cliff reserve also fluctuated last year, falling from an estimated $17.2 million at one point to an actual $5.7 million at year's end.

Teachers union officials weren't buying it. The district's explanation "doesn't make sense to me," said teachers union executive director Marshall Ogletree. "You'd be off by one (teacher) per school almost."

Asked if the district projection was far off, deputy superintendent Jim Madden suggested it be put in context, with the district having more than 100,000 students and 7,500 teachers.

"I don't think it is (far off)," he said. "It could simply mean we were 122 kids off."

The 2002 class-size amendment required districts to go to a tough, final new phase in implementation last fall: making sure the number of students in every core classroom did not exceed mandated caps. Even one student beyond the cap could have resulted in fines. Districts scrambled, in many cases hiring bunches of extra teachers.

Pinellas officials said last spring they might need 240 additional teachers, at a potential cost of $14.4 million. But superintendent Julie Janssen said the district could meet the fall caps without new hires, in part by returning some employees, such as reading and math coaches to the classroom.

The dwindling reserve is especially bad news for Pinellas.

The district has been aiming for $60 million in budget cuts next year, but legislative proposals for state education funding got even more grim in recent days.

Fred Matz, Pinellas' chief financial officer, said Tuesday that other district budget estimates are also not falling in the district's favor.

"These are projections. They could get better, they could get worse," he said. But "I'm pessimistic about them getting better."

Besides the cost for extra teachers, the district is not realizing $1.2 million it expected to save on fewer substitute teachers or $2 million in unspecified contracted services. Madden said the district has not yet looked to see why those costs are coming in higher than expected.

Also Tuesday, the board continued to wrestle with what — and potentially who — to cut.

Members took a closer look at everything from reductions in busing to many of the 400 positions being considered for elimination.